Cloth-cutting machine



Oct. 21, 1924.

H. MAIMIN ET AL CLOTH CUTTING MACHINE Fild April 27 1921 2 Sheets-Sheet.1

Oct. 219 1924- H. MAIMRN ET AL.

CLOTH CUTTING MACHINE Filed April '27. 1921 2 Sheets-Sheet 2 PatentedOct. 21, 1924.

UNITED STATES PATENT QFFICE.

HYMAN MAIMIN AND AUGUST FREDDY, OF NEW YORK, N. Y., ASSIGNORS T0 H.MAIMIN 00., INC, A CORPORATION OF NEW YORK.

CLOTH-CUTTING MACHINE.

Application filed April 2'7, 1921.

To all 20. 1 am it may concern:

Be it known that we, HYMAN MAIMIN and AUGUST FREDDY, citizens of theUnited States of America, residing at New York, county of New York, andState of New York, and whose post-ofiice address is 251 Vest 19thstreet, New York city, New York, have invented certain new and usefulImprovements in Cloth-Cutting Machines; and we do hereby declare thefollowing to be a full, clear, and exact description of the invention,such as will enable others skilled in the art to which it appertains tomake and use the same.

This invention relates to cloth-cutting machines, and particularly tothe knife guard and sharpening stones, and means for mounting them uponthe machine.

It is necessary to provide power-driven cloth-cutting machines withguards protecting the hands of the worker from the edges of the knife.In the case of rotary blades, the rear edge is permanently protected,but this is, in the nature of things, impossible with the forward orcutting edge, the guard for which cannot extend below the upper surfaceof the cloth being cut, and which must be vertically adjustable for laysof different thicknesses. At the same time the guard performs thesecondary function of the pressure foot.

It isalso necessary to provide such machines, particularly those of therotary blade type, with grinding attachments, by means of which theblade may be periodically sharpened without interference with the normaloperation of the machine. The sharpening device commonly used consistsof a pair of loosely mounted abrasive wheels carried by a supportingyoke pivotally mounted on the frame of the machine, normally urged awayfrom the blade by means of a spring, but readily movable into grindingcontact with the knife edge when the necessity arises.

As both knife guards and sharpening means are practical necessities, theproblem has arisen of providing cloth-cutting machines with both in sucha manner that they shall not mutually interfere with each other. To dothis it has been proposed to mount the grindstones wholly behind theguard so that they be swung downward into contact with the upper edge ofthe blade without necessitating any movement of the Serial No. 464,927.

guard. This is satisfactory, but a different sharpening action isobtained by swinging the stones into contact with the lower part of theblade. To do this it is, of course, necessary that the guard betemporarily moved aside during each grinding period, or positioned sofar in advance of the cutting edge as to make it practically useless asa protection. Consequently mechanisms have been devised for movin thegrindstones into contact with the blade while simultaneously moving theguard. to one side, and returning the latter to its original position asthe grindstones are swung back. These movementshave been efiectedthrough trains of gears. Such gearing is objectionable in that it isunnecessarily complex; but more than that, the ar rangement does notpermit of a rigid locking of the guard in its operative position, andthis, of course, is essential if the guard is to be effective.

It is therefore an object of the present invention to mount aknife-guard and sharpening stones on a cloth-cutting machine so that asthe stones are swung into grinding contact with the blade, the guard ismoved directly aside without the intermediary of gearing or linkage, andso that when the guard is returned to its protecting position it shallbe rigidly locked. in place. This object is attained by providing theyoke in which the grindstones are journaled with a cam surface whichengages the guard in any position of vertical adjustment and is providedat one side with a locking groove or channel in which the guard isrigidly seated and held when the stonesare in inoperative position.

A further object of the invention is to provide a simple and effectiveclamp for readily holding the guard in any position of verticaladjustment determined by the thickness of the cloth being cut.

The nature of the invention will be more clearly understood after astudy of the accompanying drawings which disclose certain preferredembodiments thereof, and in which Fig. 1 is side view of a cloth-cuttingmachine equipped with the guard and sharpening means mounted thereon inaccordance with this inyention; Fig. 2 is an end view of the samcmachine showing the guard in operative position; Fig. 3 is a side viewof the machine looking at it from the reverse side from that shown inFig. 1; Fig. 1 is an end view on an enlarged scale showing thegrindstones in operative contact with the blade and the guard movedaside into inoperative position; and Fig. 5 is a horizontal sectiontaken through the machine just below the motor casing and showing moreclearly the means for locking the guard in its operative position.

The cloth-cutting machine shown in these drawings is of the, rotaryblade type and QQmpItises a motor casing I mounted upon t. Standard 2,carried by a'ba-se plate 3. The machine is. provided with the ordinaryrotary knife 4; driven by the motor in the usual way and the machine ismoved over the cutting table and guided by means of the handle 5. Theforegoing is a common construction and forms. o part of the preseat inen n.

The, forward or cutting portion of the knife: blades is protected bymeans of a guard 61. supported in vertical; adjustment by means. of thepinch clamp 7 which is pivoted to. the, ferwaiqd side of the motorcasing. This clamp comprises two plates or wings 8, provided with h les9 through which the guard 6, passes. When the wings 8 are paralleltheseholes. 9. are in ali nment and because, of a relatively loose fitpermit longitudinal movement of the. guard. Then, h wever, these wingsare not parallel the holes 9v are, not in perfect alignment and the isclamped by means of the binding action of the wings. In order that theguard sha normally b eld 11 a fixed. p sition the clamp. is providedwith a spring 11 nermally forcing the wings ou rd y- The. longitudinal;adjustment of the guardis efliected by pinching the wings 8 together bymeans, oif'the thumb and finger until they 1.11% para lel, and thansliding the guard to thedesired position. A pinllO projecting nw sdlyfrc n ne. ofthe. ings limits their inward movement so. that when thispin con- 7 taets with the other wing the two are paral- The guard held;in its vertical and 1&1. operative position by means of anjexpa'nsionspring 12 seatedupon a lug 13, projecting outwardly from the forwardside of the motor casing, and bearing against an extension l4: of the,lower plate or wing of the pinch clamp, this. spring tending to swingthe clampabout its pivot and bring the guard into. vertical position.

The sharpening means comprisesa pair of independent abrasive wheels 20each designed to. contact with one side of the cut 'iing edge of theblade 4. These stones are loosely mounted in a yoke 15 which is pivotedat 16 upon the frame of the machine below the motor casing and above therotary blade. A spring 17 wound about the pivot pin, tends to lift'thestones upward and out or contact with the blade. The stones are swunginto contact with the blade bymeans of a series of links 18 operativelyconnected with the yoke 15 and extending rearwardly beneath the motorcasing and terminating in a trigger 19: adjacent the handle 5.

During the cutting operation the guard 6 is in its vertical position asshown in all of the figures except Fig. 4 and the grindstones areelevated. When in this position the guard 6 is rigidly held by means ofa locking channel or groove 21 on the rear surface of the yoke 15, asclearly shown in Fig. 5. VV'hen the guard is held within this groove itis practically impossible to move it laterally in any direction. Whenthe blade has become dulled through cutting and it becomes necessary tosharpenit, the operator, without taking his hand from the handleifi,pulls upon the trigger 19: This causes the oke 15 to swin downwardl .1

and assume the dotted line osition shown in Fig. .1, and at the sametime causes the guard 6 to ride outwardly over a cam sur-' face 22 onthe rear surface of the yoke. This position is shown most clearly inFig. 1. This cam surface 22, as shown most clearly in Figs. at and 5, iscontiguous tov the groove 21 and is so designed that downward "mavementof the yoke unlocks the guard and moves it laterally of the blade. Thisswings the guard and the pinch clamp 7 about the pivototthe latter andcompresses spring 12 against the lug 13'. As soon, therefore, as thegrinding operation is complete and the operator releases'the pressure ofhis finger upon trigger 19, spring throws the grindstones upwardly andspring 12 swings the guard back into its verticalposit-ion. a result ofthese two movements the guard is snapped into the locking roove 21 andheld again rigidly in its operative position.

Although the invention has been shown and described in connection with acutterof a g-rindstone for sharpening the blade, a yoke supporting thegrindsto'ne and pivot-- ally mounted on-the frame of the machine, a camsurfaceon the yoke designed to contact with the guard, and means forswinging the grindstone into contact with the blade and simultaneouslymoving the, guard outwardly on the cam surface. m

2, In a cloth-cutting machine the combination of" a cutting blade, aguard therefor,

scan nation of, a cutting blade, a guard therefor,

a grindstone for sharpening the blade, a yoke supporting the grindstoneand pivotally mounted on the frame of the machine, a locking groove inthe yoke in which the guard is normally held in operative position, acam surface on the yoke contiguous to the locking groove, and means forswinging the grindstone into contact with the blade and simultaneouslymoving the guard out of the locking groove and outwardly on the camsurface.

3. In a cloth-cutting machine the combination of a cutting blade, aguard therefor, a grindstone for sharpening the blade, a yoke supportingthe grindstone and pivotally mounted on the frame of the machine, alocking groove in the yoke in which the guard is normally held inoperative position, a cam surface on the yoke contiguous to the lockinggroove, means for swinging the grindstone into contact with the bladeand simultaneously moving the guard out of the locking groove andoutwardly on the cam'surface, and means for returning the guard to thelocking groove when the grindstone is swung into inoperative position.

at. In a cloth-cutting machine the combination of a cutting blade, aguard therefor pivotally mounted on the frame of the ma chine, agrindstone, a yoke supporting the grindstone pivotally mounted on theframe of the machine, and a cam surface on the yoke designed to contactwith the guard, the arrangement of the parts being such that as thegrindstone is swung into grinding contact with the blade the guard ridesupon the cam surface and is swung out of operative position.

5. In a cloth-cutting machine the combination of a cutting blade, aguard therefor, a clamp pivotally mounted on the frame of the machineholding the guard in adjustment, a grindstone, a yoke supporting thegrindstone and pivotally mounted on the frame of the machine, a camsurface on the yoke designed to contact with the guard in any positionof adjustment of the latter, and means for swinging the grindstone intogrinding contact with the blade, thereby causing the guard to ride uponthe cam surface and swing out of operative position.

In testimony whereof we atfix our signatures.

I-IYMAN MAIMIN. AUGUST FREDDY.

